A crop consolidating auger for a pick-up attachment usually extends the full width of the attachment and is provided with oppositely wound auger flights for gathering and consolidating the crop material in the central region of the auger from where the crop is conveyed towards processing means including, e.g., a comminuting rotor when the attachment is mounted on a forage harvester. Retractable fingers embodied in the auger, at least in the central region thereof, are a well known expedient for assisting the transfer of crop material from the pick-up device to the crop processing machine to which the device is attached.
Normally, such retractable fingers are carried on bearings which rotate on the eccentric part of a crank shaft mechanism which is coaxial with the rotational axis of the auger conveyor. The timing of the arrangement is such that, during operation, the fingers are protruding from the auger body to their maximum possible extent when oriented to the crop collecting side, i.e., the front side of the pick-up device, whereas the fingers are fully retracted when directed to the crop releasing side. In so doing, crop material lifted from the ground and presented to the consolidating auger, at least in the central portion thereof, is aggressively engaged by the protruding fingers and positively urged rearwardly where other crop transporting means are operable, such as forage harvester feed rolls or an elevating conveyor in a combine harvester feeder house.
Retractable finger arrangements of the type described is conventional in the art. For example, see U.S. Pat. No. 2,701,634, the content of which is incorporated herein by reference.
It has been experienced however that the above described finger timing position relative to the auger body is not always the best suited for all types of crops and crop conditions. Depending on, e.g., crop length, moisture content or degree of ripeness, different timing positions of the retractable fingers may be desirable in order to optimize transfer of crop material. In the arrangement shown in U.S. Pat. No. 2,701,634, mentioned above, means are provided to move the eccentric shaft relative to the pivot axis of the auger whereby a different timing position of the retractable fingers can be preset. However, among other things, this prior art arrangement suffers from the critical disadvantage that any adjustment of the finger orientation has to be performed while the harvester and attachment are inactive, meaning that the result of an adjusted finger setting is not immediately ascertainable. This leads to continuous periods of inoperation until the optimum timing is set for the existing crop conditions. Also, as crop conditions in a same field may vary widely, repeated trial and error adjustments of the finger orientation may be required leading to undesirable periods of downtime.
In addition to the above problems, crop gathering attachments occasionally become plugged due to a lump of crop material wedging between crop handling elements to the extent that it prevents normal operation. To obviate the need of manual unplugging, harvesters are commonly provided with a drive reversing mechanism which allows for reversing rotation of the crop conveying and processing means in order to evacuate the obstruction towards the front of the harvester, i.e., in a direction opposite to crop flow during normal operation. However, in the transitional area between the harvester base unit and its attachment, the auger fingers are completely retracted in the auger body, which is the normal position for the fingers during operation of the auger for releasing the transported crop appropriately. As a result, even with reverse mode available, plugging occurs necessitating shutdown to enable the operator to clear out the plug located in the transitional area.